U.S. patent number 7,985,205 [Application Number 11/226,807] was granted by the patent office on 2011-07-26 for medical catheter external bolster having strain relief member.
This patent grant is currently assigned to Boston Scientific Scimed, Inc.. Invention is credited to Mark L. Adams.
United States Patent |
7,985,205 |
Adams |
July 26, 2011 |
Medical catheter external bolster having strain relief member
Abstract
An external bolster for a medical catheter, the external bolster
comprising an integral strain relief member for diminishing the
effect of an externally-directed force applied to the medical
catheter. In a preferred embodiment, the external bolster is a
flexible, unitary member comprising a lower portion and an upper
portion. The lower portion comprises an annular base, the base
having a top surface, a bottom surface and a central opening. A
plurality of spaced apart feet extend downwardly from the bottom
surface of the base. A sleeve extends upwardly from the top surface
of the base in alignment with the central opening, the sleeve and
the central opening jointly defining a bore of uniform
cross-section. The upper portion comprises an elbow-shaped tubular
member having a vertical portion, a horizontal portion and a
longitudinal lumen. The vertical portion of the tubular member is
disposed on top of the sleeve, with its lumen aligned with the
bore. The upper portion also includes a tether for maintaining the
tubular member in a bent state, the tether having a first end
secured to the horizontal portion and a second end secured to the
vertical portion.
Inventors: |
Adams; Mark L. (Sandy, UT) |
Assignee: |
Boston Scientific Scimed, Inc.
(Maple Grove, MN)
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Family
ID: |
37865590 |
Appl.
No.: |
11/226,807 |
Filed: |
September 14, 2005 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20070078441 A1 |
Apr 5, 2007 |
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Current U.S.
Class: |
604/174;
604/523 |
Current CPC
Class: |
A61J
15/0015 (20130101); A61J 15/0061 (20130101); A61M
25/02 (20130101); A61M 25/04 (20130101); A61M
2025/0098 (20130101) |
Current International
Class: |
A61M
5/32 (20060101); A61M 25/00 (20060101) |
Field of
Search: |
;604/174,177,178,179,180 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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WO 94/08648 |
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Apr 1994 |
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WO |
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WO 95/15781 |
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Jun 1995 |
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WO |
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Primary Examiner: Stigell; Theodore J
Assistant Examiner: Carpenter; William
Attorney, Agent or Firm: Kenyon & Kenyon LLP
Claims
What is claimed is:
1. An external bolster for a medical catheter implanted in a
patient at an insertion site, said external bolster comprising: (a)
a base, said base being enlarged relative to the insertion site of
the medical catheter, said base having an opening through which the
medical catheter may be inserted; (b) a strain relief member, said
strain relief member being coupled to said base and through which
the medical catheter may be inserted, said strain relief member
comprising a tube having a first end distal to said base, a second
end proximal to said base, and a longitudinal lumen extending from
said first end of said tube to said second end of said tube, said
strain relief member further comprising a hook positioned on the
exterior of said tube proximate to said second end of said tube;
and (c) a tether, said tether having a first end and a second end,
said first end of said tether being secured to said tube at a point
proximate to said first end of said tube, said second end of said
tether comprising an opening through which said hook is removably
received to maintain the tube in a bent shape, so that said tube is
reversibly transformable between the bent shape comprising first
and second arms positioned relative to one another at an angle
greater than 0 degrees and less than 180 degrees and a straight
shape comprising a single arm, wherein said tube, when in said bent
shape, causes the medical catheter to assume a bent shape and, when
in said straight shape, causes the medical catheter to assume a
straight shape.
2. The external bolster as claimed in claim 1 wherein said first
arm and said second arm are positioned relative to one another in
said bent shape at an angle of approximately 90 degrees.
3. The external bolster as claimed in claim 1 wherein said second
arm has an end aligned coaxially with said opening of said
base.
4. The external bolster as claimed in claim 1 wherein said tether
and said strain relief member form a unitary structure.
5. The external bolster as claimed in claim 1 wherein said strain
relief member is made of a flexible material.
6. The external bolster as claimed in claim 1 wherein said base has
a top surface and a bottom surface, said external bolster further
comprising means extending downwardly from said bottom surface of
said base for elevating said base relative to the patient.
7. The external bolster as claimed in claim 1 wherein said base is
shaped to include a plurality of transverse air holes.
8. The external bolster as claimed in claim 1 wherein said base has
a top surface, said external bolster further comprising a sleeve
extending upwardly from said top surface, said sleeve being aligned
with said opening in said base and jointly defining a central bore,
said sleeve having a top end, said second end of said tube being
coaxially disposed on said top end of said sleeve.
9. The external bolster as claimed in claim 8 wherein said strain
relief member has a height of about 1-2 inches.
10. The external bolster as claimed in claim 8 wherein each of said
central bore and said longitudinal lumen is dimensioned for an
interference fit with the medical catheter.
11. The external bolster as claimed in claim 1 wherein said strain
relief member is fixed relative to said base.
12. The external bolster as claimed in claim 1 wherein said second
end of said tube is coaxially aligned with the opening in said
base, said external bolster further comprising means for elevating
said base relative to the patient to promote the circulation of air
under said base.
13. The external bolster as claimed in claim 12 wherein said angle
is approximately 90 degrees.
14. The external bolster as claimed in claim 12 wherein said base,
said elevating means, said strain relief member and said tether
form a unitary structure.
15. The combination of: (a) a medical catheter, said medical
catheter including a first end, a second end, and a longitudinal
lumen; and (b) an external bolster for the medical catheter, said
external bolster comprising: (1) a base, said base being enlarged
relative to the insertion site of the medical catheter, said base
having an opening through which the medical catheter is inserted;
(2) a strain relief device coupled to said base, said strain relief
device comprising a flexible tubular member including a first arm
terminating in a first end distal to said base, a second arm
terminating in a second end proximal to said base, and a
longitudinal lumen extending from said first end of said tubular
member to said second end of said tubular member, said first arm
and said second arm being disposed relative to one another at an
angle greater than 0 degrees and less than 180 degrees, said
medical catheter being inserted into said strain relief device,
with said first end of said medical catheter extending beyond said
first end of said first arm and said second end of said medical
catheter extending beyond said second end of said second arm, said
strain relief device further comprising a hook positioned on the
exterior of said tubular member proximate to said second end of
said tubular member; and (3) a tether, said tether having a first
end and a second end, said first end of said tether being secured
to said tubular member at a point proximate to said first end of
said tubular member, said second end of said tether comprising an
opening through which said hook is removably received to maintain
the tubular member in a bent shape, so that said tubular member is
reversibly transformable between the bent shape comprising first
and second arms positioned relative to one another at an angle
greater than 0 degrees and less than 180 degrees and a straight
shape, wherein said tubular member, when in said bent shape, causes
the medical catheter to assume a bent shape and, when in said
straight shape, causes the medical catheter to assume a straight
shape.
16. The combination of claim 15 wherein said medical catheter is a
feeding tube, an internal bolster being disposed at said second end
of said medical catheter.
17. The combination as claimed in claim 15 wherein said strain
relief device is dimensioned to provide an interference fit with
said medical catheter.
18. The combination as claimed in claim 15 wherein said first arm
and said second arm of said flexible tubular member are disposed
relative to one another at an approximate right angle.
19. The combination as claimed in claim 15 wherein said strain
relief device and said external bolster form a unitary
structure.
20. The combination as claimed in claim 15 wherein said base is
shaped to define a plurality of air holes, each air hole extending
through said base from its top surface to its bottom surface.
21. The combination as claimed in claim 15 wherein said external
bolster further includes a plurality of feet which extend
downwardly from the bottom surface of said base in a spaced apart
relationship.
22. An external bolster for a medical catheter implanted in a
patient at an insertion site, said external bolster comprising: (a)
a base, said base being enlarged relative to the insertion site of
the medical catheter, said base having an opening through which the
medical catheter may be inserted; and (b) a strain relief member,
said strain relief member being coupled to said base, said strain
relief member comprising a tube having a longitudinal lumen through
which the medical catheter may be inserted, said strain relief
member further including a catch positioned on the exterior of said
tube; and (c) a tether, said tether having a first end and a second
end, said first end of said tether having means for releasably
engaging said catch to maintain the tube in a bent shape, so that
said tube is transformable between the bent shape comprising first
and second arms positioned relative to one another at an angle
greater than 0 degrees and less than 180 degrees and a straight
shape comprising a single arm, wherein said tube, when in said bent
shape, causes the medical catheter to assume a bent shape and when
in said straight shape, causes the medical catheter to assume a
straight shape.
23. An external bolster for a medical catheter implanted in a
patient at an insertion site, said external bolster comprising: (a)
a base, said base being enlarged relative to the insertion site of
the medical catheter, said base having an opening through which the
medical catheter may be inserted; (b) a strain relief member, said
strain relief member being coupled to said base and through which
the medical catheter may be inserted, said strain relief member
comprising a tube having a first end distal to said base, a second
end proximal to said base, and a longitudinal lumen extending from
said first end of said tube to said second end of said tube, said
strain relief member further comprising a hook positioned on the
exterior of said tube; and (c) a tether, said tether having a fixed
end and a free end, said fixed end of said tether being fixedly
secured to said tube, said free end of said tether having an
opening through which said hook is removably received so that, when
said hook is received within said opening and, thus, said free end
of said tether is secured to said tube, said tube assumes a bent
shape comprising first and second arms positioned relative to one
another at an angle greater than 0 degrees and less than 180
degrees, and so that, when said hook is not received within said
opening and, thus, said free end of said tether is not secured to
said tube, said tube assumes a straight shape comprising a single
arm.
24. The external bolster as claimed in claim 22 wherein said catch
is a hook and wherein said means for releasably engaging said catch
comprises an opening in said tether through which said catch is
removably received.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to external bolsters of the
type used to retain an implanted medical catheter in the body of a
patient and relates more particularly to external bolsters of the
aforementioned type that include means for relieving strain applied
to the medical catheter.
Certain patients are unable to take food and/or medications
transorally due to an inability to swallow. Such an inability to
swallow may be due to a variety of reasons, such as esophageal
cancer, neurological impairment and the like. Although the
intravenous administration of food and/or medications to such
patients may be a viable short-term approach, it is not well-suited
for the long-term. Accordingly, the most common approach to the
long-term feeding of such patients involves gastrostomy, i.e., the
creation of a feeding tract or stoma between the stomach and the
upper abdominal wall. (A less common approach involves jejunostomy,
i.e., the creating of a feeding tract or stoma leading into the
patient's jejunum.) Feeding is then typically performed by
administering food through a catheter or feeding tube that has been
inserted into the feeding tract, with one end of the feeding tube
extending into the stomach and being retained therein by an
internal anchor or bolster and the other end of the feeding tube
extending through the abdominal wall and terminating outside of the
patient.
Although gastrostomies were first performed surgically, most
gastrostomies are now performed using percutaneous endoscopy and
result in the implantation of a feeding tube/internal bolster
assembly (also commonly referred to as a percutaneous endoscopic
gastrostomy (PEG) device) in the patient. Two of the more common
techniques for implanting a PEG device in a patient are "the push
method" (also known as "the Sacks-Vine method") and "the pull
method" (also known as "the Gauderer-Ponsky method"). Information
regarding the foregoing two methods may be found in the following
patents, all of which are incorporated herein by reference: U.S.
Pat. No. 5,391,159, inventors Hirsch et al., which issued Feb. 21,
1995; U.S. Pat. No. 5,167,627, inventors Clegg et al., which issued
Dec. 1, 1992; U.S. Pat. No. 5,112,310, inventor Grobe, which issued
May 12, 1992; U.S. Pat. No. 4,900,306, inventors Quinn et al.,
which issued Feb. 13, 1990; and U.S. Pat. No. 4,861,334, inventor
Nawaz, which issued Aug. 29, 1989.
According to the push method, one end of an endoscope is intubated
(i.e., inserted) into a patient's mouth and is passed through the
esophagus into the stomach. After distension of the stomach by
inflation, an entry site on the abdomen is identified using the
endoscope for transillumination, and an incision is made by passing
the tip of a needle coupled to an outer cannula through the
abdominal and stomach walls and into the stomach. One end of the
outer cannula remains outside of the body and acts as a stop to
prevent the external end of the needle from falling into the
stomach. A snare is inserted into the stomach via the endoscope and
is looped over the inserted end of the needle. The snare is then
"walked" up the needle until the outer cannula is snared. The
snared cannula is then pulled externally to tack the cannula to the
stomach and, in turn, to secure the stomach wall to the abdominal
wall. The needle is then removed while keeping the cannula in
place. A first end of a flexible guidewire is then passed through
the cannula and into the stomach where it is grasped by the snare,
the second end of the guidewire remaining external to the patient.
The endoscope and the snare are then withdrawn from the mouth of
the patient to deliver the first end of the guidewire.
A push-type catheter implanting assembly is then inserted over the
first end of the guidewire and is pushed over the guidewire towards
its second end. The push-type catheter implanting assembly
typically comprises a gastrostomy feeding tube, the gastrostomy
feeding tube having a dome-shaped internal bolster disposed at its
trailing end and having a tubular dilator serially connected to its
leading end. The gastrostomy feeding tube and the internal bolster
are typically made of a soft, biocompatible material, like silicone
rubber, and may form a unitary structure. The dilator, which tapers
in outer diameter from its trailing end to its leading end, is
typically made of polyethylene or a like material which is stiffer
than silicone but which still possesses some flexibility.
Advancement of the push-type catheter implanting assembly over the
guidewire continues until the front end of the dilator reaches the
cannula and pushes the cannula out through the abdominal wall of
the patient. The front end of the dilator is then pulled through
the abdominal wall until the front end of the gastrostomy feeding
tube emerges from the abdomen and, thereafter, the internal bolster
at the rear end of the gastrostomy feeding tube engages the stomach
wall. The guidewire is then removed from the patient. The clinician
then re-intubates the patient with the endoscope and uses an
optical channel in the endoscope to inspect whether the internal
bolster is properly seated in the stomach.
If the internal bolster is properly placed against the stomach
wall, a length of the externally-extending portion of the implanted
gastrostomy feeding tube is then typically cut and removed from the
implanted tube to reduce the externally-extending portion of the
tube to a desired length (typically about 4-6 inches). (The removal
of the leading end of the gastrostomy feeding tube also results in
the removal of the dilator, which is connected thereto.)
The pull method is similar in some respects to the above-described
push method, the pull method differing from the push method in
that, after the cannula is snared and the needle is removed
therefrom, a first end of a suture is inserted through the cannula
and into the stomach where it is grasped by the snare, the second
end of the suture remaining external to the patient. The endoscope
and the snare are then withdrawn from the mouth of the patient to
deliver the first end of the suture. The first end of the suture is
then coupled to the leading end of a pull-type catheter implanting
assembly, the pull-type catheter implanting assembly typically
comprising a gastrostomy feeding tube having an internal bolster at
its trailing end and a plastic fitting at its leading end. The
plastic fitting typically has a barbed rear portion mounted within
the leading end of the feeding tube and a conical front portion
that serves as a dilator, said conical front portion tapering in
diameter from the leading end of the feeding tube to a front tip. A
wire loop is fixed to the front tip of the plastic fitting, the
first end of the suture being tied to the wire loop. Using the
second end of the suture, the pull-type catheter implanting
assembly is then pulled retrograde through the patient until the
gastrostomy feeding tube emerges from the abdomen of the patient
and the internal bolster engages the stomach wall of the patient.
Next, as is the case in the push method, the clinician then
re-intubates the patient with the endoscope in order to visually
inspect the placement of the internal bolster within the stomach.
If the bolster is properly seated in the stomach, the
externally-extending portion of the implanted gastrostomy feeding
tube is then typically cut to a desired length.
Regardless of whether a PEG device is implanted by the
above-described push method, by the above-described pull method or
by another method, complications may arise if the PEG device is
positioned too far internally within the patient. More
specifically, if the trailing (i.e., internal) end of the PEG
device, especially the internal bolster, is positioned too far
internally within the patient, the PEG device can cause blockages
in the patient's stomach or otherwise interfere with stomach
function. Furthermore, if the trailing end of the PEG device is
positioned too far internally within the patient, the leading
(i.e,. external) end of the PEG may be drawn entirely into the
patient's stomach, possibly causing great harm to the patient.
For the above reasons, it is customary to use an externally located
device, typically referred to in the art as an external bolster, to
retain the external portion of the PEG device outside of the
patient. An external bolster typically comprises an enlarged
annular member that is shaped to include a central bore through
which the external portion of the PEG device may be inserted.
Preferably, the central bore is appropriately dimensioned to
provide an interference (i.e., frictional) fit between the external
bolster and the feeding tube fed therethrough. In use, the leading
(i.e., external) end of the implanted PEG device is inserted
through the central bore in the external bolster as far as
possible. Due to the significant interference fit between the outer
diameter of the feeding tube and the inner diameter of the external
bolster, forceps or the like may be used to facilitate the
insertion of the leading end of the feeding tube through the
central bore of the external bolster. The feeding tube is
preferably advanced through the central bore until the bottom
surface of the external bolster is drawn into direct contact with
the patient's skin in the area surrounding the wound site.
Positioned in this manner, the external bolster effectively anchors
the implanted PEG device in its proper position and prevents any
migration of the device into the patient's stomach. Although not
needed in all cases, it may be desirable in certain instances for
the external bolster to be sutured to the patient's skin.
Although external bolsters of the type described above function
satisfactorily to prevent the external end of an implanted PEG
device from being withdrawn into a patient's stomach, most such
external bolsters do not additionally provide strain relief to
dissipate the effect of an externally-directed pulling force
applied to the PEG device. Such strain relief is highly desirable
as it has been found that certain patients (e.g., patients
suffering from dementia or Alzheimer's disease) often knowingly or
unknowingly attempt to remove implanted PEG devices from their
bodies by pulling on the external end of the PEG device. As can be
readily be appreciated, the application of a sufficiently great
pulling force on the external end of an implanted PEG device can
ultimately result in, among other things, the ill-advised removal
of the PEG device from the patient and/or significant injury to the
patient at the site of implantation (e.g., tearing of sutures,
damage to the stoma, etc.).
In response to the above problem, certain external bolsters have
been devised that provide strain relief to an implanted feeding
tube. For example, in U.S. Pat. No. 6,471,676, inventor DeLegge,
which issued Oct. 29, 2002, and which is incorporated herein by
reference, a catheter retention device is disclosed that is
designed to relieve strain caused by physical force exerted against
the catheter. The retention device, which is unitary in design and
constructed out of a flexible material, such as silicone or
thermoplastic rubber, includes a base component which supports
first and second substantially cylindrical retention ring housing
components, the second retention ring housing component being
positioned on the base such that the axis of its centrally disposed
bore is out of axial alignment with the centrally disposed bore for
the first retention ring housing component. In use, the portion of
an implanted feeding tube which exits the patient's body is first
passed through a bore formed in the base component. The feeding
tube is then curved at approximately a ninety degree (90.degree.)
angle and is threaded through the central bore of the first
retention ring housing component. The feeding tube is then looped
around at an angle of approximately two hundred-seventy degrees
(270.degree.), preferably on a plane parallel to the base component
so as to be threadably insertable through the central bore of the
second retention ring housing component whose axis is perpendicular
to that of the bore of the first retention ring housing component.
Once the feeding tube is fed through the base component and both
retention ring housing components as described above, the base is
attached to the skin of the patient using any one of a number of
attachment means or methods known in the art such as sutures,
staples, adhesive tapes or liquid adhesives.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a novel
external bolster of the type suitable for use in retaining within a
patient an implanted medical catheter, such as a gastrostomy
feeding tube.
It is another object of the present invention to provide an
external bolster as described above that addresses at least some of
the shortcomings present in connection with existing external
bolsters.
It is still another object of the present invention to provide an
external bolster as described above that is adapted to relieve
strain applied to an implanted medical catheter secured
thereto.
It is yet still another object of the present invention to provide
an external bolster that is inexpensive to manufacture and is easy
to use.
Therefore, according to one feature of the present invention, there
is provided an external bolster for a medical catheter implanted in
a patient at an insertion site, said external bolster comprising
(a) a base, said base being enlarged relative to the insertion site
of the medical catheter, said base having an opening through which
the medical catheter may be inserted; and (b) a tubular strain
relief member, said tubular strain relief member being coupled to
said base and through which the medical catheter may be inserted,
said tubular strain relief member having a first arm, a second arm
and a longitudinal lumen, said longitudinal lumen extending through
said first and second arms, said first arm and said second arm
being positioned relative to one another at an angle, said angle
being greater than 0 degrees and less than 180 degrees.
According to another feature of the present invention, there is
provided an external bolster for a medical catheter implanted in a
patient at an insertion site, said external bolster comprising (a)
a base, said base being enlarged relative to the insertion site of
the medical catheter, said base having an opening through which the
medical catheter may be inserted; and (b) a tubular strain relief
member, said tubular strain relief member being coupled to said
base and through which the medical catheter may be inserted, said
tubular strain relief member having a longitudinal lumen, said
longitudinal lumen having a first portion and a second portion,
said first portion and said second portion being positioned
relative to one another at an angle, said angle being greater than
0 degrees and less than 180 degrees.
According to yet another feature of the present invention, there is
provided the combination of (a) a medical catheter, said medical
catheter including a first end, a second end, and a longitudinal
lumen; and (b) a strain relief device, said strain relief device
comprising a flexible tubular member including a first arm
terminating in a first end, a second arm terminating in a second
end, said first arm and said second arm being disposed relative to
one another at an angle greater than 0 degrees and less than 180
degrees, said medical catheter being inserted into said strain
relief device, with said first end of said medical catheter
extending beyond said first end of said first arm and said second
end of said medical catheter extending beyond said second end of
said second arm.
According to still yet another feature of the present invention,
there is provided a strain relief device for a medical catheter,
said strain relief device comprising (a) a flexible tubular member
dimensioned to receive a medical catheter, and (b) a tether coupled
to said flexible tubular member at a pair of locations, said tether
retaining said flexible tubular member in a bent state.
For purposes of the present specification and claims, various
relational terms like "top," "bottom," "proximal," "distal,"
"upper," "lower," "front," and "rear" are used to describe the
present invention when said invention is positioned in or viewed
from a given orientation. It is to be understood that, by altering
the orientation of the invention, certain relational terms may need
to be adjusted accordingly.
Additional objects, as well as features and advantages, of the
present invention will be set forth in part in the description
which follows, and in part will be obvious from the description or
may be learned by practice of the invention. In the description,
reference is made to the accompanying drawings which form a part
thereof and in which is shown by way of illustration certain
embodiments for practicing the invention. These embodiments will be
described in sufficient detail to enable those skilled in the art
to practice the invention, and it is to be understood that other
embodiments may be utilized and that structural changes may be made
without departing from the scope of the invention. The following
detailed description is, therefore, not to be taken in a limiting
sense, and the scope of the present invention is best defined by
the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are hereby incorporated into and
constitute a part of this specification, illustrate various
embodiments of the invention and, together with the description,
serve to explain the principles of the invention. In the drawings
wherein like reference numerals represent like parts:
FIGS. 1(a) and 1(b) are top perspective and section views,
respectively, of a conventional external bolster of the type
adapted for use with an implanted PEG device to prevent the inward
migration of the PEG device into a patient;
FIG. 2 is a perspective view of the external bolster shown in FIGS.
1(a) and 1(b), the external bolster being mounted on a PEG device,
the PEG device being shown implanted in the body of a patient, the
patient's body being shown in fragmentary section;
FIGS. 3(a) and 3(b) are top perspective and section views,
respectively, of a first embodiment of an external bolster
constructed according to the teachings of the present
invention;
FIG. 4 is a perspective view of the external bolster shown in FIGS.
3(a) and 3(b), the external bolster being shown mounted on a PEG
device, the PEG device being shown implanted in the body of a
patient, the patient's body being shown in fragmentary section;
FIGS. 5(a) and 5(b) are perspective and rear views, respectively,
of a second embodiment of an external bolster constructed according
to the teachings of the present invention; and
FIGS. 6(a) and 6(b) are perspective views of a third embodiment of
an external bolster constructed according to the teachings of the
present invention, the external bolster being shown with its
tubular strain relief member in a bent state and in a straight
state, respectively.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIGS. 1(a) and 1(b), there are shown top
perspective and section views, respectively, of a conventional
external bolster of the type designed to prevent an implanted
medical catheter, such as a PEG device, from being drawn into a
patient's body, the conventional external bolster being represented
generally by reference numeral 11.
Bolster 11, which is a unitary member typically made of silicone
using conventional molding techniques, includes an enlarged annular
base 13 having a substantially flat top surface 15 and a
substantially flat bottom surface 17. A plurality of air holes 19
are provided in base 13 in a spaced apart relationship. Each air
hole 19 is generally circular in lateral cross-section and extends
through base 13 from top surface 15 to bottom surface 17. Together,
air holes 19 facilitate the aeration of a stoma site, as will be
described further below.
A plurality of feet 21 are formed on bottom surface 17 of base 13
along its outer periphery in a spaced apart relationship. Each foot
21 is in the shape of a block which is generally rectangular in
lateral cross-section. With bolster 11 properly mounted on a
feeding tube, feet 21 are designed to contact the skin of a patient
in the area surrounding a stoma site. In this manner, feet 21 serve
(i) to keep bolster 11 out of contact with the stoma site and to
minimize the surface area of bolster 11 that contacts the patient's
skin, thereby limiting any irritation to the patient resulting from
contact with bolster 11; and (ii) to elevate bottom surface 17 of
base 13 away from the patient's skin, thereby promoting the
aeration of the stoma site and reducing the risk of bacterial
infection.
A short sleeve 23 is centrally located on base 13 and extends
orthogonally upwardly from top surface 15 of base 13. Sleeve 23
includes a lower neck portion 25 of smaller outer diameter and an
upper flange portion 27 of greater outer diameter. Sleeve 23 and
base 13 jointly define an elongated central bore 29 which is of a
uniform circular shape in lateral cross-section therethrough.
Central bore 29 is sized and shaped to receive a conventional
feeding tube. Preferably, central bore 29 is appropriately
dimensioned so that a strong interference (i.e., friction) fit is
established between external bolster 11 and a feeding tube which is
inserted through central bore 29. In this manner, external bolster
11 can be secured tightly to a feeding tube, the enlarged size of
bolster 11 acting as a stop, or barrier, for limiting the inward
migration of the feeding tube into the patient.
Referring now to FIG. 2, external bolster 11 is shown mounted on an
implanted PEG device to prevent the implanted PEG device from
migrating into a patient's stomach. As can be seen, the implanted
PEG device comprises a feeding tube 31, feeding tube 31 having an
internal end 33 and an external end 35, internal end 33 being
shaped to define a dome-shaped internal bolster. As shown, the
implanted PEG device is being pulled externally (i.e., away from
the patient or in the direction of arrow A) so that internal end 33
engages the stomach wall 37 of a patient and presses stomach wall
37 against the abdominal wall 39 of the patient. External bolster
11, which is inserted over external end 35 of tube 31 and slid down
into contact with abdominal wall 39, is oriented so that feet 21
are pressed against abdominal wall 39 and so that sleeve 23 extends
away from abdominal wall 39. If necessary, forceps or the like may
be used to facilitate the insertion of external end 35 of feeding
tube 31 through bore 29 of bolster 11.
As noted above, central bore 29 is dimensioned so as to create a
significant interference fit between feeding tube 31 and bolster
11. As a result, with feet 21 uniformly disposed in contact against
the patient's skin outside the area of the stoma, external bolster
11 effectively functions as an anchor to prevent feeding tube 31
from inwardly migrating into the patient's stomach. In addition,
feet 21 serve to space bottom surface 17 of base 13 substantially
away from the patient's skin in order to permit the circulation of
air around the stoma site. Air holes 19 increase the degree of air
circulation around the stoma site and may be used, if desired, to
suture bolster 11 to the patient.
It should be noted that external bolster 11 is not limited to use
with a PEG device, but rather, may be used with any type of medical
catheter (e.g., a jejunostomy feeding tube, a drainage tube,
etc.).
As noted above, it has been found that certain patients often
intentionally pull on the externally-extending portion of an
implanted PEG device in a misguided attempt to remove the PEG
device from their bodies. In addition, it is not uncommon for
medical care providers or for the patients, themselves, to
accidentally pull on the externally-extending portion of an
implanted PEG device while performing everyday activities. Because
external bolster 11 provides no strain relief (i.e., no
diminishment of the externally-directed force transmitted to the
PEG device) when feeding tube 31 is pulled externally, this force
can ultimately result in, among other things, the dislodgement of
the PEG device and/or significant injury to the patient (e.g.,
tearing of stoma, etc.).
In addition, although the PEG device of FIG. 2 is shown with
feeding tube 31 being pulled directly upright, it should be
understood that, when no external force is applied to the PEG
device, the external portion of feeding tube 31 will go limp and
rest upon the top surface of abdominal wall 39. As can readily be
appreciated, such contact between the external portion of feeding
tube 31 and abdominal wall 39 may, over time, cause irritation to
the patient's skin, leading to ulcers or the like.
Referring now to FIGS. 3(a) and 3(b), there are shown perspective
and section views, respectively, of a first embodiment of an
external bolster constructed according to the teachings of the
present invention, said external bolster being represented
generally by reference numeral 111. As will be described below in
further detail, bolster 111 is adapted to be slidably mounted over
an implanted medical catheter, such as a PEG device, in order to
absorb (i.e., to diminish or to relieve) undesirable
externally-directed forces that are exerted on the
externally-extending portion of said PEG device.
Bolster 111, which is preferably a molded unitary structure made of
a flexible material, such as a 40A durometer silicone, comprises a
lower portion 112 and an upper portion 113. Lower portion 112 is
identical in structure to bolster 11. Upper portion 113 comprises
an elbow-shaped (i.e., 90 degree) tubular strain relief member 115
and a tether 117. Tubular member 115 is shaped to include a first
arm 115-1 terminating in a first end 119, a second arm 115-2
terminating in a second end 121, and a longitudinal lumen 123. As
will be discussed below, tubular member 115 has a height h of
approximately 1-2 inches; in this manner, a substantial length of
the externally-extending portion of an implanted catheter extending
through bolster 111 is elevated relative to a patient's skin.
Second end 121 of tubular member 115 is disposed at the upper end
of sleeve 23, with lumen 123 aligned with bore 29. Lumen 123
preferably has a diameter equal to that of bore 29 so that a strong
interference (i.e., friction) fit may be established between
tubular member 115 and a catheter inserted through lumen 123. As
will be discussed below, because tubular member 115 is bent at a 90
degree angle, the externally-extending portion of an implanted
catheter that is inserted through tubular member 115 extends
perpendicularly relative to the insertion angle of the implanted
catheter in the patient. As a result, an externally-directed
pulling force applied to the externally-extending portion of the
implanted catheter is substantially reduced in magnitude along the
insertion angle of the implanted catheter.
Tether 117, which causes tubular member 115 to be held in a bent
shape, is preferably a thin strengthening member having a first end
125 and a second end 127. First end 125 of tether 117 is secured to
tubular member 115 at a point proximate to first end 119 and second
end 127 of tether 117 is secured to tubular member 115 at a point
proximate to second end 121.
To facilitate the threading of an implanted feeding tube through
bolster 111, one or both of bore 29 of sleeve 23 and lumen 123 of
member 115 may be coated with one or more lubricious substances.
Also, an anti-microbial coating may be applied to some or all of
the outer surfaces of bolster 111 to ward off bacterial infection
in the area of the stoma.
It should be noted that, although bolster 111 is disclosed in the
present embodiment as being a unitary structure, bolster 111 need
not be a unitary structure and may be formed by constructing lower
portion 112 and upper portion 113 as separate pieces which are
thereafter joined together by suitable means (e.g., adhesives,
fasteners, complementary threaded portions, etc.). In fact, lower
portion 112 and upper portion 113 may be separately formed and then
coupled together in such a manner as to permit upper portion 113 to
rotate or swivel on lower portion 112. Alternatively, upper portion
113 could even be utilized in combination with lower portion 112
without actually physically joining upper portion 113 to lower
portion 112.
Also, in another embodiment (not shown), upper portion 113 could be
replaced in its entirety with a block of silicone having an
elbow-shaped (or otherwise bent) channel whose lower end is aligned
with bore 29.
Finally, it should be recognized that lower portion 112 could be
replaced with other conventional or novel external bolster
designs.
Referring now to FIG. 4, external bolster 111 is shown mounted over
a PEG device that has been implanted in a patient, the PEG device
comprising a tube 31 having an internal end 33 and an external end
35, internal end 33 being in the form of a dome-shaped internal
bolster. As can be seen, as a result of the bend in tubular member
115, an externally-directed withdrawal force F applied to external
end 35 of tube 31 is directed at approximately a right angle
relative to the portion of feeding tube 31 that extends through
abdominal wall 39 and stomach wall 37 of the patient. As a result,
only a small portion of the withdrawal force is actually
transmitted to feeding tube 31 in a direction opposite to the
insertion angle of the feeding tube.
As can also be seen in FIG. 4, another desirable aspect of bolster
111 is that, due in part to the height h of tubular member 115, a
substantial length of the externally-extending portion of tube 31
is elevated relative to the patient's skin. As a result of keeping
this length of tubing away from the patient's skin, the patient is
rendered less susceptible to irritation, ulcers and other
complications of the type caused by having the feeding tube contact
the patient's skin for a prolonged period of time.
Referring now to FIGS. 5(a) and 5(b), there are shown various views
of a second embodiment of an external bolster constructed according
to the teachings of the present invention, said external bolster
being represented generally by reference numeral 311.
Bolster 211 is similar in most respects to bolster 111, the
principal difference between the two bolsters being that bolster
211 includes a series of perforations 213 that extend the
respective heights of tubular member 215, sleeve 223 and base 233
and that may be used, when torn, to form a longitudinal slit, said
slit facilitating the insertion and removal of a catheter into and
out of bolster 211.
Referring now to FIGS. 6(a) and 6(b), there are shown various views
of a third embodiment of an external bolster constructed according
to the teachings of the present invention, said external bolster
being represented generally by reference numeral 311.
Bolster 311 is similar in most respects to bolster 111, the
principal difference between the two bolsters being that bolster
311 includes a tubular member 315 and a tether 317, instead of
tubular member 115 and tether 117, respectively. Tubular member 315
differs from tubular member 115 in that tubular member 315 is
shaped to include a hooked catch 316 that extends outwardly a short
distance from vertical arm 315-1 of member 315. Tether 317 differs
from tether 117 in that tether 317 has a first or fixed end 325
that is fixedly secured to the horizontal arm 315-2 of tubular
member 315 and a second or free end 327 that includes an opening
329 adapted to receive catch 316 in such a way as to permit second
end 327 of tether 317 to be releasably secured to tubular member
315. In this manner, when one wishes to insert a catheter through
member 315 or to remove a catheter from member 315, one may first
disconnect second end 327 of tether 317 from tubular member 315,
thereby permitting tubular member 315 to assume its natural,
straight shape. As can be appreciated, insertion of a catheter
through the lumen of tubular member 315 or removal of a catheter
from the lumen of tubular member 315 is easier when tubular member
315 is straight than when tubular member 315 is bent. After a
catheter has been inserted through or removed from member 315,
second end 327 of tether 317 may be reconnected to tubular member
315 to return tubular member 315 to its bent state.
It is to be understood that numerous modifications could be made to
bolsters 111, 211 and 311 without departing from the spirit of the
present invention. For example, although tethers 117, 217 and 317
are designed to provide right angle bends in tubular members 115,
215 and 315, respectively, tethers 117, 217 and 317 could be used
to achieve a different angular bend in tubular members 115, 215 and
315, respectively.
For example, the angular bend in tubular members 115, 215 and 315
could be increased to an angle greater than 90.degree. and less
than 180.degree.. As can be appreciated, increasing the bend angle
of tubular members 115, 215 and 315 above 90.degree. (i) decreases
the degree of strain relief provided by the tubular members but (2)
increases the degree of separation between the externally-extending
portion of the feeding tube and the patient's skin.
Alternatively, the angular bend in tubular members 115, 215 and 315
could be decreased to an angle greater than 0.degree. and less than
90.degree.. As can be appreciated, decreasing the bend angle of
tubular members 115, 215 and 315 below 90.degree. (i) increases the
degree of strain relief provided by the tubular members but (2)
decreases the degree of separation between the externally-extending
portion of the feeding tube and the patient's skin.
Moreover, whereas tethers 117, 217 and 317 have been described
above as being integrally formed with tubular members 115, 215 and
315, respectively, one could replace tethers 117, 217 and 317 with
filaments, threads or the like, one or both ends of which are
bonded or insert-molded to tubular members 115, 215 and 315.
Furthermore, one could reinforce the bend in tubular members 115,
215 and 315 with a braid, a bent rod, a spring, an oversleeve or
co-extruded tough material.
The embodiments of the present invention described above are
intended to be merely exemplary and those skilled in the art shall
be able to make numerous variations and modifications to them
without departing from the spirit of the present invention. All
such variations and modifications are intended to be within the
scope of the present invention as defined in the appended
claims.
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